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Title: Residual ferroelectricity in barium strontium titanate thin film tunable dielectrics

Loss reduction is critical to develop Ba{sub 1−x}Sr{sub x}TiO{sub 3} thin film tunable microwave dielectric components and dielectric energy storage devices. The presence of ferroelectricity, and hence the domain wall contributions to dielectric loss, will degrade the tunable performance in the microwave region. In this work, residual ferroelectricity—a persistent ferroelectric response above the global phase transition temperature—was characterized in tunable dielectrics using Rayleigh analysis. Chemical solution deposited Ba{sub 0.7}Sr{sub 0.3}TiO{sub 3} films, with relative tunabilities of 86% over 250 kV/cm at 100 kHz, demonstrated residual ferroelectricity 65 °C above the ostensible paraelectric transition temperature. Frequency dispersion observed in the dielectric temperature response was consistent with the presence of nanopolar regions as one source of residual ferroelectricity. The application of AC electric field for the Rayleigh analysis of these samples led to a doubling of the dielectric loss for fields over 10 kV/cm at room temperature.
Authors:
;  [1] ; ; ;  [2]
  1. Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)
  2. Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27607 (United States)
Publication Date:
OSTI Identifier:
22308546
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BARIUM COMPOUNDS; ELECTRIC FIELDS; ENERGY STORAGE; FERROELECTRIC MATERIALS; LOSSES; MICROWAVE RADIATION; PHASE TRANSFORMATIONS; STRONTIUM COMPOUNDS; TEMPERATURE RANGE 0273-0400 K; THIN FILMS; TITANATES; TRANSITION TEMPERATURE